The present invention broadly relates to gas engines and, more specifically, pertains to a new and improved construction of a gas engine having a regulatable gas inlet valve.
Generally speaking, the gas engine of the present invention comprises a cylindrical expansion chamber closed by the gas inlet valve and a piston reciprocating in the cylinder as well as a gas supply conduit leading from a pressurized gas container to the gas inlet valve.
In other words, the gas engine of the present invention comprises a regulatable gas inlet valve having an inlet side, a substantially cylindrical expansion chamber closed by the regulatable gas inlet valve, a reciprocatable piston arranged within the expansion chamber, a pressurized gas container and a gas supply conduit leading from the pressurized gas container to the gas inlet valve.
A gas engine of this type is known from the British Pat. No. 1,553,678, published Oct. 3, 1979. In this gas engine, a piston is reciprocatingly arranged within a cylindrical expansion chamber. The piston is connected with a crankshaft by a connecting rod. The crankshaft carries the propeller of a model aircraft. The cylinder head comprises a central bore closeable by a gas inlet valve. A ball lying in the cylinder head on the side remote from the cylinder space or expansion chamber upon a valve seat behind the central bore serves as a valve body. The cylinder head communicates through a gas supply conduit with a pressurized gas container containing carbon dioxide. The gas pressure presses the ball onto the valve seat and holds the gas inlet valve closed. The gas inlet valve is opened by a protrusion formed on the upper side of the piston in order to admit gas to flow into the expansion chamber. The gas inlet valve operates on the principle of a check valve or non-return valve. The protrusion pushes against the ball and raises it from the valve seat when the piston is located in the region of top dead-center at the end of its return stroke and the beginning of its working stroke. When shutting off the engine, the piston can come to a stop in the course of its return stroke shortly before attaining top dead-center or even in the top dead-center region. A restart of the motor is in this case difficult, since the piston must execute at least one partial stroke against full gas pressure in starting. It can also occur that the gas motor start in the incorrect direction of rotation for this reason. In toys, such as toy cars and other powered devices having gear-reduction transmissions between the engine shaft and the starter engagement shaft, a restart can even become impossible.